I’m looking for a process for powder coating screws (usually heads only) in large quantities. Are you aware of any systems currently in use or available? L. M.
Plastic safety glass lenses are non-conductive and should not attract much powder. Charged powder particles are primarily attracted to grounded surfaces, although they can be attracted to ungrounded surfaces to some extent. Some spray cleaners will neutralize the surface of the safety glass lens and should reduce the problem. Check with your safety glass supplier for an appropriate cleaner.
There was one company who made a system to apply powder coatings onto screws and other hardware components, but they went out of business. There may be other companies that make such systems today, but I am unaware of them. Most systems that do this work will coat all the screw surfaces (threads and all). If you want to just coat the screw heads, you will have to have a system custom designed for that purpose.
I have several customers who have specialty systems that apply powder coating to screws, bolts and specialty fasteners. Each of these systems are custom built for that specific task. I can’t discuss them very much, since I am bound by numerous confidentiality agreements. However, they either use hard tooling masks or blow-off and/or vacuum systems to ensure that the powder only goes where they want it. This type of design can be very expensive, so don’t even think about going this route unless you have a boatload of screws to coat.
If you have a short-term need to coat screws, look at using a hanger or fixture that has holes in it to hold the screw and protect the shaft from powder during spray activities. Then just coat them as you would any other flat part and cure them. The biggest problem you will have is removing the screws from the fixture. The powder coating will create a bond between the fixture and the part that will need to be broken before you can remove the screw. Good luck.